Pastilles are currently formed by preparing a granulated product, fed to compacting machines, which divide the product into given amounts, and compact each into a pastille. To be effectively compacted and produce firm, homogeneous pastilles of a given hardness, the granulated product must have a specific grain size, which also depends on the characteristics of the ingredients of the product.
Granulated products are currently produced using various types of mills for grinding the powdery ingredients to a given grain size (normally no higher than 100 microns). This grinding step is followed by a mixing step, in which other ingredients, such as maltodextrine or gum, are added to the ground ingredients, and the resulting mixture is granulated to modify its grain size, make it more compressible, and improve its organoleptic qualities.
At present, the above process is normally carried out using so-called fluid-bed systems, in which the powdery mixture is first moistened, normally by adding water solutions, and is then mixed and dried. Drying is performed by forming a layer of moist mixture, and blowing hot air through it to gradually form particles of normally 0.5 to 1 mm in size.
Alternatively, the moist mixture is dried in microwave driers.
EP0673644 describes a method and system for preparing a granulated product containing one or more active principles for an effervescent solution.
EP039697 B1 describes a method of producing a granulated powder containing potassium salt.
DE3337770 describes a rotary fluid-bed granulator.
Though widely used, known systems, while only providing for adequate output, are extremely bulky and expensive to both produce and maintain.
Moreover, cleaning known systems, when making production changes or switching from one product or recipe to another, is a long, painstaking job.